I didn't want to disappoint you guys by not continually asking my questions. I have a body and a back, just waiting for the lens. Does 120 film work in a 220 back? I was wondering if there would be any focus problems.. I am also trying to figure out this grid. It is 5x5 squares, and than an xtra set of lines around the square about 3-4 millimeters out. How can you tell where the image lays on the back from where the image is in the grid? Thanks!